Synthesis and spectroscopic characterization of novel 2-amido substituted benzimidazo[1,2-a]quinolines

U ovom radu opisana je sinteza i spektroskopska karakterizacija novih 2-amido supstituiranih benzimidazo[1,2-a]kinolina. Novi spojevi priređeni su klasičnim reakcijama organske sinteze. Aciklički prekursor E-2-[2-(p-cijanofenil)etenil]benzimidazol 3 pripravljen je iz 2- metilbenzimidazola i 4-cijanobenzaldehida. Fotokemijskom ciklizacijom etanolne otopine spoja 3 dobiven je 2-cijanobenzimidazo[1,2-a]kinolin 4. Iz cijano supstituiranog derivata 4 u kiseloj vodenoj otopini priređena je benzimidazo[1,2-a]kinolin-2-karboksilna kiselina 5 koja u reakciji sa SOCl2 daje glavni prekursor za sintezu amida, benzimidazo[1,2-a]kinolin-2- karbonil-klorid 6. 2-amido supstituirani benzimidazo[1,2-a]kinolini 7-9 dobiveni su reakcijom benzimidazo[1,2-a]kinolin-2-karbonil-klorida 6 s odgovarajućim aminima. Strukture novopriređenih spojeva okarakterizirane su UV/Vis i fluorimetrijskom spektroskopijom, te su potvrđene 1H i 13C NMR spektroskopijom.This work presents the synthesis and spectroscopic characterization of novel 2-amido substituted benzimidazol[1,2-a]quinolines. Novel compounds were prepared by classical reactions of organic chemistry. Acyclic precursor E-2-[2-(p-cyanophenyl)etenyl]benzimidazol 3 was prepared from 2-metylbenzimidazole and 4-cyanobenzaldehyde. 2-cyanobenzimidazo[ 1,2-a]quinoline 4 was prepared by photochemical cyclization of ethanolic solution of compound 3. Benzimidazo[1,2-a]quinoline-2-carboxylic acid 5 was prepared by acidic hydrolysis from compound 4. In the reaction of carboxylic acid 5 with SOCl2 the corresponding benzimidazo[1,2-a]quinoline-2-carbonylchloride 6 as a main precursor for the synthesis of targeted amides, was prepared. 2-amido substituted benzimidazo[1,2-a]quinolines 7-9 are were obtained in the reaction with corresponding amines. All newly prepared compounds were characterized by UV/Vis and fluorimetric spectroscopic, while the structures were confirmed by means of 1H i 13C NMR spectroscopy